Both faster-than-light (FTL) travel and time travel are concepts that are currently beyond our technological capabilities and are purely speculative in nature. However, if we consider the known principles of physics, achieving FTL travel appears to be more difficult than time travel.
According to our current understanding of physics, specifically Albert Einstein's theory of relativity, the speed of light is an absolute cosmic speed limit. Objects with mass would require an infinite amount of energy to accelerate to or exceed the speed of light. This is known as the "lightspeed barrier" or "Einstein's cosmic speed limit." Many theories and hypotheses have been proposed to bypass this limitation, such as warp drives or wormholes, but they remain speculative and have significant theoretical and practical challenges associated with them.
On the other hand, time travel, although also highly speculative, does not directly violate any fundamental laws of physics. The possibility of time travel is often discussed within the framework of general relativity, where concepts like wormholes, time dilation, and closed timelike curves are explored. While these concepts present various paradoxes and theoretical challenges, they do not face the same direct contradiction with the lightspeed barrier.
It is important to note that both FTL travel and time travel are purely hypothetical at this point, and any claims about their feasibility are highly speculative. Our current scientific understanding suggests that achieving either of these concepts would require a profound advancement in our knowledge of physics and the discovery of new phenomena or principles that we are not aware of at present.